Project Summary/Abstract The neurological and sleep-related sensory disorder called Restless Legs Syndrome (RLS) occurs with moderate to severe intensity in 2 [unreadable] 3% of the population of the United States. It seriously alters life producing a profound, persistent loss of sleep and uncomfortable or even painful leg sensations, including an urge to move the legs. The severe sensations of urge-to-move and discomfort dominate patients waking thoughts. The sensations cannot be ignored. Relief generally comes only with walking or with medication. Good diagnosis and treatment need accurate evaluation of RLS severity and symptoms occurrence. Unfortunately RLS severity has been evaluated mainly by global rating scales or assessment of the motor symptoms of RLS virtually ignoring direct assessment of the occurrence and severity of the sensory symptoms that define the disorder. Three major problems with assessment occur because symptoms are: masked by activity, worse at night while generally not present during a clinic visit, and variable over days. These contribute to large placebo effects and diagnostic errors noted in clinical trials. One laboratory assessment of the sensory symptoms of RLS removes two of these problems. It requires patients to sit with their legs stretched-out while resting awake, relaxed and not-moving for 60 minutes. During this suggested immobilization test (SIT) sleep EEG is recorded along with the subject's report of degree of leg discomfort obtained every 5 minutes. The rest condition provokes RLS symptoms thus stimulating expression of the full degree of severity of the disorder, particularly when done at night. Data from a SIT test in the lab indicate good metrics for evaluating RLS except for the problem of symptom variability and the somewhat unnatural environment. This project will develop technology to avoid these last problems by transferring this test to the home environment where it can be repeated for at lest 3 nights. A special `sensory symptoms during home- based self-imposed rest evaluator' (SHIRE) will be developed that reminds a subject when to do the test, records the subject's leg position and at 5-minute intervals the ratings of sensory discomfort in the legs and stores this information for at least 5 home SIT (H-SIT) episodes. Successful implementation of the H-SIT requires some unique design considerations focused on promoting and recording compliance as well as having an easy-to-use system that a patient can be expected to manage at home without technical assistance. The proposed system would be the first to be easily assessable for measuring occurrence of the RLS sensory symptoms under standardized and repeatable conditions designed to stimulate their full expression. It holds the potential for informing the patient as well as the clinician of the degree of RLS severity. It will shift emphasis in RLS to more direct evaluation of the defining sensory symptoms of RLS. Thus it will serve pressing needs of research, clinical trials and clinical management of RLS. Project Narrative The neurological disorder of restless legs syndrome (RLS) produces strange uncomfortable feelings of a need to move the legs that can be painful and often cannot be ignored. This project will develop for the first time a monitor that a patient can use at home to accurately evaluate the occurrence and severity of these abnormal sensory symptoms that define RLS. This better evaluation of RLS severity provides better diagnosis and treatment evaluation of RLS.